This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Membrane protein structure determination remains a frontier in structural biology. Growth of diffraction quality crystals is a bottleneck, while growth of crystals diffracting to high-resolution is rare. Using a new strategy, we grew crystals of four integral-membrane proteins, which are currently at different stages of crystallographic characterization. Once crystals of membrane proteins have been grown, the screening process is more involved than for soluble proteins. Often, little diffraction is observed at the home generator, and since the optimization of crystallization conditions is based on feedback from diffraction rather than from the visual quality of the crystals, much more synchrotron time is required to determine each structure.